Support is requested to continue the development and application of immobilized enzyme technology to problems in biochemical analysis and medical therapy. The concept of immobilized enzymes has been broadened in the investigator's laboratory to include the study of immobilized antibody and immobilized inorganic catalyst activity. The enzyme electrode project will exploit our ability to covalently bond enzyme to Teflon membrane etched by a suspension of sodium metal in naphthalene. A bedside glucose monitor based on this sensor is undergoing clinical trial. Radioimmunoassay using gel entrapped antibody developed in our laboratory requires no pipetting or centrifugation steps. This technology is now undergoing transfer to our industry partner. Methods for gel RIA of large antigens are under development. Red blood cell loading of therapeutic enzyme and other medication is undergoing evaluation as a new drug delivery system. Circulatory compartment half life for this drug-delivery system is measured in days, not just seconds or minutes as for synthetic liposome carriers. In the area of immobilized inorganic catalyst activity, we plan further development and evaluation of a hemodialysis-based system of extracorporeal respiratory gas exchange based on oxygenation by transmembrane catalysis of hydrogen peroxide.